Anesthetic vaporizer

ABSTRACT

An anesthetic vaporizer includes a housing for the anesthetic fluid which includes an inlet passage having a connection for a first bypass flow and a second pressure compensation flow within the housing. The pressure compensation flow is through a spiral tube which leads into a chamber for the anesthetic fluid and the bypass flow is directly to the discharge of the device. The control also includes a flow control valve from the fluid chamber which provides for a flow of the fluid from the chamber to the discharge in accordance with the temperature conditions of the fluid within the chamber.

1Jnited States Patent reiiing 14 1 Mar. 28, 1972 [s41 ANESTHETIC VAPORIZER 3,521,634 7/1970 Goodyear et a1. ..12s/1ss 3,420,232 1/1969 Bickford [72] Inventor. :22; Georg Breiling, Gross Gronau, Ger- 3,172,405 3/1965 Sugg [73] Assignee: Dragerwerk Aktiengesellschaft, Lubeck, Primary Examiner-Richard A. Gaudet Germany Assistant Examiner-J. B. Mitchell [22] Filed: May 7 1970 Attorney-McGlew and Toren [21] App1.No.: 35,534 [57] ABSTRACT An anesthetic vaporizer includes a housing for the anesthetic [30] Foreign Application Priority Data fluid which includes an inlet passage having a connection for a May 12 1969 Germany ..1 19 24 227.4 bypass and a mpmmm within the housing. The pressure compensation flow is 52 11.s.c1 ..12s/1ss s Spiral tube which leads a chambe' s 1 1 1m. (:1. ..A6lm 17/00 anesthetic fluid and the bypass flow is directly to the discharge [58] Field of Search ..128/188, 186, 189, 190, 196, of the device- The control also includes a flow control valve 128/197, 209-211; 261/39, 46, 79, 99, 104, DIG from the fluid chamber which provides for a flow of the fluid 65 from the chamber to the discharge in accordance with the temperature conditions of the fluid within the chamber. 56 R f Cited 1 8 creates 1 Claim, 2 Drawing Figure v UNITED STATES PATENTS V m 3 1 1 r. f q"'I"" "T.':i1Tifllljliff'j 8/ 54 L. I I 1- I8 A 23 g I g -5 A 1 ,5 6 28 7 I so 29 2 8 50 1 Z 9 PATETEDMWB I972 SHEET 1 BF 2 villa/ 7K INI/E/VTOR Hons Georg Breiling ATTORNEYS PATENTED MR 2 8 1972 SHEET P. BF 2 WVE/VTOR Hans Georg Breiling ATTORNEYS SUMMARY OF THE INVENTION This invention relates in general to the construction of vaporizing devices and in particular, to a new and useful anesthetic vaporizer which includes an arrangement for enriching a gas stream which is passed through the vaporizer with an anesthetic contained in the vapor and with means to regulate the discharge to a desired concentration.

Anesthetic Vaporizers are known which are equipped with so-called automatic temperature compensation devices in order to prevent the anesthesia gas which is administered to a patient to vary in concentration during temperature fluctuations of the gas. Some anesthetic Vaporizers include means for checking the temperature continuously by the anesthetist. The anesthetist checks the temperature with a thermometer and uses a reference table for adjusting the valves which connect the supply of the anesthetic to the patient. The valves are adjusted manually in accordance with the observed temperature. Some anesthetic Vaporizers include a so-called bypass line which branches off from a gas inlet of the vaporizer and ends at the gas outlet thereof. It is known to install in the bypass line, or in the lines leading through the vaporizer, throttles or valves of different construction by which the ratio of the gas stream is controllable. It has also been proposed to provide such equipment with temperature compensators. The disadvantages of the known devices is that when closing the valve of one of the valves connected in the bypass line or in the vaporizer line the resistance of the vaporizer increases considerably so that the flow of gas is throttled to an impermissible extent.

The invention provides an anesthetic vaporizer which includes means for ensuring that the flow resistance does not increase too much when any valve in the system is shut off. The invention includes a hand wheel adjustment for one of the valves which operates, in or near its end position, to bring into an opened position a valve which is connected in a gas inlet aperture of the anesthesia apparatus with the gas outlet aperture thereof. In accordance with the invention, the housing of the device includes a passage which bypasses the anesthesia fluid and through which the gas can flow when the anesthetic vaporizer is turned off. Thereby the resistance of the vaporizer connected in the gas line is reduced in the switched off state to any desired value in accordance with the bypass control. In order to avoid, in the shut off condition, that any gas passes through the vaporizer at all the valve may be designed as a double valve and can in the end position provide a complete shut off of the line to the anesthesia zone. In order furthermore to ensure that a pressure does not develop into the vaporizer chamber when the latter is disconnected, it further may be provided with means, such as a triple valve construction, to provide a venting of the vaporizer chamber to the atmosphere.

Accordingly, it is an object of the invention to provide an improved vaporizer which includes a housing defining a passage which divides into a flow to a chamber containing an anesthetic fluid and a flow through a bypass from the inlet to the outlet substantially directly, and which includes means for adjusting the valve for flow of the gas outwardly from the anesthetic liquid chamber which also provides means for regulating the flow through the bypass line and/or a vicinity of the fluid chamber.

A further object of the invention is to provide an anesthetic vaporizer which is simple in design, rugged in construction and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a vertical section through an anesthetic vaporizer constructed in accordance with the invention; and

FIG. 2 is a section taken along the line A-A of FIG. 1.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings in particular, the invention embodied therein comprises a vaporizer device which includes a housing generally designated 50 which defines an interior fluid chamber 12 for an anesthetic liquid 52. The housing 50 includes an inlet 1 which is adapted to be connected to a gas supply line (not shown). The interior of the housing is divided into two separate gas streams at the location 2 and a portion of the gas stream passes through a bore 3 into a pressure compensation coil 4 and through a line 5 into a cylindrical jacket space 6 of the vaporizer. The jacket space 6 is defined between wick shells 7 and 8 and the line 5 connects into this space 6. The wick shells 7 and 8 include a gas conductor spiral or guide 9 therebetween so that the anesthesia gas is guided around the outside of guide 9 in the cylinder jacket space 6 downward in a spiral path. The gas enters into the vaporizer chamber 12 at a point 10 through bores at the interior of wall 11. On this path the gas stream saturates itself with the vapor of the anesthetic 52 and the gas then flows through a bore 30 of a cylinder part 29 and upwardly through a space 15 which is regulated by a control valve 54 which is movable in accordance with temperature changes in the vapor chamber 12 as sensed by sensing means, generally designated 56. The sensing means 56 is in the form of an expansible and contractable bellows 58 which is connected to a control member 60 of the valve 54. The gas flows through the control valve space 15 into the discharge space 16 which leads to the discharge aperture 18. The chamber 32 around the bellows is completely filled with liquid.

A second partial gas stream passes through a bypass passage 17 which is defined by another movable valve member 66 and a fixed portion 67 of the housing. The gas moves through the passage 17 and into the space 16 where it becomes mixed with the first partial stream and the gas mixture leads through the discharge aperture 18. The valve member 66, which is biased to a setting position by a spring 68, is threadably connected to an actuator such as a hand wheel 19. When the hand wheel 19 is rotated so as to displace it in respect to the valve member 66 there is also a control of the bypass passage 17 and a regulation preferably of the venting of the chamber 12 by a movable valve or piston valve.

The control valve means for regulating the flow through the bypass 17 and also for venting the fluid chamber 12 includes the movable piston valve 21 which includes an upper face which bears against the lower end face 22 of the adjustable wheel 19. The wheel 19 is provided with a surface 22 which when the vaporizer is switched off, causes or permits the valve piston 21 to be moved by its associated biasing spring 28 into an upper position. In this upper position which is not indicated in the drawings, the piston valve 21 closes the passage from gas inlet aperture 1 through the bypass passage 17 and in respect to the pressure compensation spiral passage 4 of the other divided gas flow. At the same time, the constriction 23 of the piston valve 21 clears the aperture 24 to the annular line 25 which is indicated in FIG. 2. Behind the space 16 this line 25 opens into the line leading to the outlet 18. The lower piston part 26 clears the venting aperture 27 of the vaporizer space 12 so that the latter communicates with the atmosphere. The pressure piston 21 is held in the position shown by the compression spring 28.

When the anesthesia apparatus is switched off, therefore, the entire gas stream is conducted past the vaporizer chamber and past the bypass valve near the branch line 25, so that the resistance can be reduced to any desired value. In the switched ofi state moreover, the access from the gas admission line 1 to the vaporizer chamber 12 is closed off and the latter deaerated.

The venting bore 27 is located below the level of the valves and 17 so that any connected anesthesia system is admitted only with the intentionally adjusted concentrations.

What is claimed is:

1. An anesthetic vaporizer comprising a housing defining a chamber for an anesthetic fluid, a housing inlet and a housing discharge, first passage means in said housing from said inlet to said discharge, second passage means in said housing from said inlet through said chamber to said discharge, control valve means for said first and second passages for regulating the flow of fluid from said inlet through said first and second passage means to said discharge, a movable piston valve member in said inlet being movable for regulating the flow of fluid from said inlet into said first passage means, and a movable actuator member connected to said control valve means for adjusting said control valve means and being movable to engage said movable piston valve member for shifting said piston valve member to vary the flow of fluid into said first passage means, said control valve means comprising a first movable valve member having an expansible portion disposed in said fluid chamber and being movable upon expansion and contraction of said expansible portion, a second movable valve member concentrically arranged around said first valve member and defining therewith a portion of said second passage means extending from said inlet to said fluid chamber and from said fluid chamber to said discharge, said second movable valve member also defining a portion of said first passage means from said inlet to said discharge, said movable actuator member comprising a hand wheel rotatably engaged with said second movable valve member and having a portion overlying said piston valve member and engageable with said piston valve member for shifting said piston valve member during rotation thereof.

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1. An anesthetic vaporizer comprising a housing defining a chamber for an anesthetic fluid, a housing inlet and a housing discharge, first passage means in said housing from said inlet to said discharge, second passage means in said housing from said inlet through said chamber to said discharge, control valve means for said first and second passages for regulating the flow of fluid from said inlet through said first and second passage means to said discharge, a movable piston valve member in said inlet being movable for regulating the flow of fluid from said inlet into said first passage means, and a movable actuator member connected to said control valve means for adjusting said control valve means and being movable to engage said movable piston valve member for shifting said piston valve member to vary the flow of fluid into said first passage means, said control valve means comprising a first movable valve member having an expansible portion disposed in said fluid chamber and being movable upon expansion and contraction of said expansible portion, a second movable valve member concentrically arranged around said first valve member and defining therewith a portion of said second passage means extending from said inlet to said fluid chamber and from said fluid chamber to said discharge, said second movable valve member also defining a portion of said first passage means from said inlet to said discharge, said movable actuator member comprising a hand wheel rotatably engaged with said second movable valve member and having a portion overlying said piston valve member and engageable with said piston valve member for shifting said piston valve member during rotation thereof. 